Sick sea lion numbers drop one year after crisis

ROB VARELA/THE STAR
Patient 9, a sea lion yearling, swims in the ocean after being released by Channel Islands Marine & Wildlife Institute volunteers Shelle and Ryan Williams, of Ventura.

Ventura County Star

The scratching at the door came early on Valentine’s Day.

When someone opened the door of the Rincon Parkway home, a small, skinny sea lion pup shuffled in, finding a table and curling up beneath it.

It was Patient 6, emaciated and sick.

As of late last week the Channel Islands Marine & Wildlife Institute in Gaviota was up to 37 patients rescued in Ventura County this year.

“Mostly what we’re seeing is skinny, behind the curve on eating, just not doing well after weaning,” said Dr. Sam Dover, a veterinarian and the center’s executive director.

That’s fairly typical for this time of year as pups start to wean. The numbers have kept the center busy, although it has far fewer patients than last year, Dover said.

Rescue centers from San Diego to Santa Barbara were pushed to their limits after hundreds of emaciated pups started showing up in January 2013.

More than 1,550 had been admitted for rehabilitation by April 2013 — at least five times more than normal. The National Oceanic Atmospheric Administration declared an “unusual mortality event” for California sea lions in late March 2013.

That move allowed officials to gather a team of experts to investigate and try to pinpoint a cause. One leading theory has been that a sardine decline left the sea lions with less fatty and less high-energy food, like rockfish and market squid.

Findings are still inconclusive, but the unusual mortality event has ended, said Sharon Melin, a wildlife biologist with the National Marine Mammal Lab in Seattle. She has studied sea lions on San Miguel Island, off the Ventura County coast, for 28 years.

Typically, about 25,000 to 28,000 pups are born each June in the rookery on San Miguel. Pups typically stay with their mothers until about April or May.

But when Melin and others went out in September 2012, the pups were much thinner than normal, she said. By February 2013, they were not faring any better.

“These are pups still at the colony,” Melin said. They still had their mothers to help them. By then, others had started showing up along the coast emaciated and dehydrated, long before they should have been weaned.

“We think for some reason they thought it would be better to go out on their own,” Melin said. But they were too small, not fat enough and not capable enough to find food.

“If an adult female was struggling, a little pup doesn’t have much of a chance,” she said.

By April 2013, things seemed like they were turning around a bit on the island, Melin said. The pups had gained weight but still were small. Despite concerns that those pups also would show up stranded, a lot of them did fine.

This year the trend toward improvement seems to be continuing.

“They were still a little bit small,” Melin said of the pups at San Miguel this year. But they were doing quite well, she said.

Compared with the 37 marine mammals stranded this year in Ventura County — nearly all of them young sea lions — volunteers and staff members had rescued 77 by this time last year, said Ruth Dover, who runs the Gaviota rescue and rehab center with her husband, Sam. Eight of the sea lions, including Patient 6, have recovered and been released back into the ocean near the Channel Islands.

The Dovers got a permit and opened the clinic about eight years ago in a former school off U.S. Highway 101. Classrooms were turned into a hospital and surgery room. Outdoor rehab pools were added to the grounds. On a recent afternoon, sea lions took a dip, stretched out poolside in the sun or wandered into and out of large crates. They are moved out there when they are getting ready to be released.

The center has been busier than in some years, but finding young sea lions stranded around this time is not out of the ordinary. Determining what a normal number would be is hard, as weather and other conditions change each year.

“I don’t think there is a normal,” Sam Dover said. “Every year is different.”

Discovering how last year’s crisis will affect the overall sea lion population will take a few years, officials said.